*Ahem*.
Since 3D models are only in 1.09.4, I decided to post these here. You can use these textures for anything you want, even a brand-new fangame.
Modern Sonic Retexture:
This was meant for the NiGHTS Ideya Drone:
Shadow the Hedgehog:
And that's it. If you want the mesh to go with these, go here.

OpenGL doesn't restrict itself to an indexed palette, so MD2 skins can be true-color images. Theoretically, so could every other graphic in the game, but the formats used by the game only support indexed colors.

Sorry if someone already answered this but if you mean SATAM by "Sonic the Hedgehog" if I remember, Tails' shoes were either exactly like Sonics or a reverse colored Sonic's, I think it might've been the latter, and by that I mean exactly like Sonic's, except the colors were inverted.